# Trig Functions

There are several simple trig functions that you definitely have to remember and in this article, we will help you to remember all of them easily.

Scholar's Tip: Try using the TOA, CAH, SOH method to remember the simple trig functions easily

Let's see on how we go about it. Take for example, sine
.We know that sine
is the ratio of the opposite side of the triangle to the hypotenuse .So we have come up with ‘SOH' meaning that sine ? is equal to the opposite side over the hypotenuse. This is the same for ‘CAH' and ‘TOA'. ‘CAH' means that cosine
is equal to the adjacent over the hypotenuse. Similarly, ‘TOA' means that tangent
is equal to the opposite side over the adjacent.

Remembering these simple trig functions wasn't that hard was it? Let's look at an overview of these trig functions.

(sine) (SOH)

(cosine) (CAH)

(tangent) (TOA)

(cotangent)

(secant)

(cosecant)

In the event that the denominator in the trigonometry function (sine
, cosine
) is equated to zero, the entire trigonometry function will be undefined.

For every real angle , there exists a value for cosine
and sine
. As such ,the angle
does not have to be acute. The values of sine
and cosine
(sec
and cosec
as well) is restricted between – 1 and 1 . Values for tangent and cot
, on the other hand, can extend to positive and negative infinity.

After learning these trig functions, proceed on to find out more about the trig ratio.

Return to Trigonometry Help or Basic Trigonometry .